1. Field of the Invention
The present invention relates to a suction noise muffler for a hermetic compressor, and particularly to an improved suction noise muffler for a hermetic compressor which is capable of enabling a smooth flow of a refrigerant gas and reducing a suction noise by forming a predetermined shaped guide path for a refrigerant gas flow and a plurality of noise reducing sections.
2. Description of the Conventional Art
Referring to FIGS. 1 through 3, a conventional hermetic compressor will now be explained. A housing 1 includes a motor unit 4 having a stator 2 and a rotor 3, with the stator 2 and the rotor 3 being arranged in a lower portion inside the housing 1. A crank shaft 5 is inserted into the center portion of the rotor 3 of the motor unit 4.
An eccentric portion 6 is formed in an upper portion of the crank shaft S. A piston 8 is inserted within a cylinder 7 arranged in an upper portion inside the housing 1, with the piston 8 reciprocating within the cylinder 7 in cooperation with the rotation of the eccentric portion 6 of the crank shaft 5.
A valve plate 9 is arranged in a portion of the cylinder 7 for controlling the flow of the refrigerant gas. A suction noise muffler 10 and a discharge noise muffler (not shown) are arranged in the valve plate 9.
A cylinder head cover 11 is disposed in an upper portion of the suction noise muffler 10 and the discharge noise muffler (not shown).
An elongated wall 14 is arranged inside the suction noise muffler 10. A first noise reducing section 12 and a second noise reducing section 13 are defined by the elongated wall 14. An inlet 15 is formed in a portion of the suction noise muffler 10, through which inlet 15 the refrigerant gas is introduced.
An insertion hole 16 is formed in a predetermined portion of the elongated wall 14, into which hole 16 a guide tube 17 is inserted for guiding the flow of the refrigerant gas.
An outlet 19 is formed opposite the inlet 15 of the suction noise muffler 10 in order for the refrigerant gas to be guided to a suction hole 18 of the valve plate 9.
The operation of the conventional hermetic compressor will now be explained with reference to FIGS. 1 through 3.
First, when current voltage is supplied to the motor unit 4, the rotor 3 rotates, and the crank shaft 5 drivingly inserted into the rotor 3 is rotated thereby. The eccentric portion 6 of the crank shaft 5 causes the piston 8 to horizontally reciprocate within the cylinder 7.
The suction force which is generated in accordance with the horizontally reciprocating movement of the piston 8 serves to introduce the refrigerant gas into the cylinder 7 through the suction noise muffler 10.
The above-described process will now be explained in more detail.
The refrigerant gas is introduced into the system through the inlet 15 of the suction noise muffler 10. The noise contained in the introduced refrigerant gas is reduced by the first noise reducing section 12, and is guided to the second noise reducing section 13 through the guide tube 17, and the noise is further reduced by the second noise reducing section 13. Thereafter, the refrigerant gas is discharged through the outlet 19 and is introduced into the cylinder 7 through the suction hole 18 of the valve plate 9.
The refrigerant gas introduced into the cylinder 7 is compressed and discharged by the reciprocating movement of the piston 8.
However, since the suction noise muffler 10 is fabricated by a ultrasonic melting method after the guide tube 17 is inserted into the insertion hole 16, the productivity is decreased due to the complicated fabrication process.
In addition, since the refrigerant gas is not smoothly flown in the system due to a burr which is formed during the ultrasonic melting process, the performance of the suction noise muffler 10 is degraded.
FIGS. 4 and 5 illustrate another conventional hermetic compressor which was disclosed in the U.S. Pat. No. 5,304,044. As shown therein, a motor unit 21 is arranged in an upper portion inside a housing 20, with the motor unit 21 including a rotor (not shown) and a stator (not shown) for driving a crank shaft (not shown). A cylinder 22 and a piston 23 are arranged in a lower portion inside the housing 20.
On side of a valve plate 24 is attached to one side of the cylinder 22. Another side of the valve plate 24 is attached to a cylinder head cover 25 in cooperation with a predetermined engaging member (not shown).
The suction noise muffler 26 includes a cover 27, an upper casing 28, and a lower casing 29. The cover 27 is engaged to the upper portion of the upper casing 28 engaged to the upper portion of the lower casing 29.
A cylindrical first chamber 30 is vertically formed in the lower casing 29, and a connection duct 31 is formed within the lower casing 29 and beside the first chamber 30.
In the upper casing 28, a second chamber 32 is formed above the first chamber 30. A hole 33 is formed in a wall formed between the first chamber 30 and the second chamber 32 in order for the refrigerant gas to communicate between the first chamber 30 and the second chamber 32. A third chamber 34 is formed beside the second chamber 32 and within the upper casing 28, with the third chamber 34 communicating with the second chamber 32.
A first insertion hole 36 is formed in a lower portion of the connection duct 31 of the lower casing 29, with a capillary tube 35 being inserted into the first insertion hole 36. A discharge hole 37 is formed in a lower portion of the connection duct 31 in order for the refrigerant gas to be discharged through the discharge hole 37.
An insertion groove 38 is formed above the cylinder head cover 25 in order for the connection duct 31 of the suction noise muffler 26 to be tightly attached to the insertion groove 38.
A small suction room 39 is formed in a lower portion of the insertion groove 38 in order for a predetermined amount of the refrigerant gas discharged from the discharge hole 37 to be gathered therein.
A discharge room 40 having a larger space than that of the suction room 39 is formed in the lower portion of the suction room 39.
A suction port 41 is formed in the valve plate 24 at a portion lower than the suction room 39 in order for the refrigerant gas introduced into the suction room 39 to be easily introduced into the cylinder 22.
A clamp 42 shown in FIG. 4 is disposed above the cylinder head cover 25 for clamping the suction noise muffler 26 and the capillary tube 35.
The operation of another conventional hermetic compressor will now be explained with reference to FIGS. 4 and 5.
First, when the rotor (not shown) of the motor unit 21 rotates, the crank shaft (not shown) drivingly connected with the rotor is rotated, so that the piston 23 reciprocates within the cylinder 22.
The suction force generated in the cylinder 22 in cooperation with the reciprocating movement of the piston 23 causes the refrigerant gas to be introduced into the suction noise muffler 26, and the noise contained in the thusly introduced refrigerant gas is gradually reduced through the first chamber 30, the second chamber 32, the third chamber 34, and the connection duct 31.
Thereafter, the refrigerant gas is introduced into the cylinder 22 through the discharge hole 37, the suction room 39, and the suction port 41, and is compressed by the piston 23 and is moved to the discharge room 40.
However, since all of the first chamber 30, the second chamber 32, the third chamber 34, and the connection duct 31 causes a resonant effect therein, a noise reducing effect is decreased.
FIGS. 6 through 8 illustrate still another conventional hermetic compressor which was disclosed in the U.S. Pat. No. 5,201,640. As shown therein, a motor unit 46 having a stator 44 and a rotor 45 is disposed in a lower portion inside a housing 43. A crank shaft 47 is inserted into the rotor 45.
A compression unit having a cylinder 48 and a piston 49 is disposed at an upper portion inside the housing 43. The piston 49 connected to the crank shaft 47 reciprocates within the cylinder 48.
One side of a valve plate 50 is attached to one side of the cylinder 48. A cylinder head cover 51 is arranged at another side of the valve plate 50.
A discharge room 52 is formed above the cylinder head cover 51, and an engaging groove 54 is formed below the discharge room 52 for being engaged with a shell-shaped suction noise muffler 53.
The suction noise muffler 53 includes a lower casing 55 and an upper casing 56 which are coupled together by a clamp 57.
An inlet 58 is formed in a lower portion of the lower casing 55 in order for the refrigerant gas to be introduced through the inlet 58. A guide pipe 59 is disposed in the central portion of the lower casing 55 in order for the refrigerant gas to be guided thereby, with the guide pipe 59 being curved horizontally and vertically.
A wall 61 is vertically formed in the outer portion of the guide pipe 59 and defines a suction noise reducing section 60 at both sides of the wall 61.
A plurality of input/output holes 62 are formed in both sides of the guide pipe 59 in order for the refrigerant gas to be introduced and discharged therethrough.
A suction duct 64 is formed at one end of the guide pipe 59 in order for the refrigerant gas flowing along the guide pipe 59 to be guided to the inlet 63 of the valve plate 50.
An outlet 65 is formed in an upper end portion of the suction duct 64 in order for the refrigerant gas to be discharged through the outlet 65.
The operation of the conventional hermetic compressor will now be explained with reference to FIGS. 6 through 8.
First, when the motor unit 46 receives current voltage, the crank shaft 47 drivingly connected with the rotor 45 of the motor unit 46 is rotated, and the piston 49 connected with the crank shaft 47 reciprocates within the cylinder 48.
The suction force generated in the cylinder 48 in cooperation with the reciprocating movement of the piston 49 is guided to the guide pipe 59 through the inlet 58 of the suction noise muffler 53.
The refrigerant gas introduced into the guide pipe 59 is discharged to the suction noise reducing section 60 through the inlet/outlet holes 62, and the noise contained in the refrigerant gas is reduced therein. The noise-reduced refrigerant gas is introduced into the guide pipe 59 through the inlet/outlet holes 62, and the thusly introduced refrigerant gas moves along the suction duct 64 and is introduced into the inlet 63 formed in the valve plate 50.
The refrigerant gas introduced into the cylinder 48 through the inlet 63 is compressed by the, piston 49, and is moved to the discharge room 52 of the valve plate 50.
Meanwhile, a lubricating oil gathered in the bottom portion of the housing 43 is upwardly moved by a centrifugal force generated by a rotational force of the crank shaft 47, and is sprayed to the motor unit 46 and friction sections of the system, so that a cooling operation with respect to the heated portions of the system and a lubricating operation are performed. Thereafter, the thusly sprayed lubricating oil is again gathered at the bottom portion of the housing 43. The above-described operation is repeatedly performed.
However, since in order to dispose the suction noise muffler 53 in the housing 43, the upper casing 56 must be assembled to the system after the guide pipe 59 is inserted into the lower casing 55, so that the productivity is significantly decreased.